Precursor particle for preparation of cathode active material for secondary battery and novel precursor powder containing same

Abstract

Disclosed are novel precursor particles for preparing a cathode active material including transition metal precursor particles containing one or more transition metals, and one or more of an alkali metal and an alkaline earth metal, wherein the alkali metal and the alkaline earth metal are contained in one or more of inner and outer parts of the transition metal precursor particles, and a novel precursor powder including the novel precursor particles.

The invention claimed is: 
     
       1. A novel precursor particle for preparing a cathode active material comprising:
 a transition metal precursor particle containing one or more transition metals; and 
 one or more of an alkali metal and an alkaline earth metal, 
 wherein the alkali metal and the alkaline earth metal are contained in one or more of inner and outer parts of the transition metal precursor particle, 
 wherein the novel precursor particle has a composition represented by the following Formula 1:
   [(1-x-Y)A 2 CO 3 *xAOH*yA 2 O]/[(1-a-b)M(OH) 2 *aMOOH*bM(OH 1-c ) 2 ]  (1)
 
 
 wherein 
 0≤x≤1, 0≤y≤1, 0≤a≤1, 0≤b≤1, 0≤c≤1; 
 A is at least one alkali metal and/or alkaline earth metal; and 
 M comprises one or more transition metals stable in a tetracoordinate or hexacoordinate structure, and 
 wherein the molar ratio (A/M) of total alkali metal and/or alkaline earth metal (A) to total transition metal (M) is more than 0 and is not more than 1.5. 
 
     
     
       2. The novel precursor particle according to  claim 1 , wherein the alkali metal comprises one or more of Li (lithium) and Na (sodium). 
     
     
       3. The novel precursor particle according to  claim 1 , wherein the novel precursor particle is a secondary granule formed by aggregation between a plurality of primary particles. 
     
     
       4. The novel precursor particle according to  claim 1 , the alkali metal or alkaline earth metal is present in at least one of the following states:
 (a) coating the surface of the primary particles and/or secondary granules; 
 (b) present in the voids between the primary particles; and 
 (c) present in the inner part of primary particles and/or secondary granules. 
 
     
     
       5. The novel precursor particle according to  claim 1 , wherein one or more of the alkali metal and the alkaline earth metal are contained in both the inner part and the outer part of the transition metal precursor particle. 
     
     
       6. The novel precursor particle according to  claim 1 , wherein parameters in the Formula 1 satisfy one of the following combinations (i) to (vii):
 (i) x=0, y=0 
 (ii) y=0, x=1 
 (iii) x=0, x+y=1 
 (iv) y= 0 , 0<x<1 
 (v) x=0, 0<y<1 
 (vi) 0<x<1, 0<y<1, x+y=1 
 (vii) 0<x<1, 0<y<1, x+y<1. 
 
     
     
       7. The novel precursor particle according to  claim 1 , wherein parameters in Formula 1 satisfy one of the following combinations (i) to (vii):
 (i) a=0, b=0 
 (ii) b=0, a=1 
 (iii) a=0, a+b=1 
 (iv) b=0, 0<a<1 
 (v) a=0, 0<b<1 
 (vi) 0<a<1, 0<b<1, a+b=1 
 (vii) 0<a<1, 0<b<1, a+b<1. 
 
     
     
       8. A novel precursor particle for preparing a cathode active material comprising:
 a transition metal precursor particle containing one or more transition metals; and 
 one or more of an alkali metal and an alkaline earth metal, 
 wherein the alkali metal and the alkaline earth metal are contained in one or more of inner and outer parts of the transition metal precursor particle, wherein the novel precursor particle has a composition of the following Formula 2:
   [(1-x-y)A 2 CO 3 *xAOH*yA 2 O]/MO 2-a   (2)
 
 
 wherein 
 0≤x≤1, 0≤y≤1, 0≤a≤1; 
 A is at least one alkali metal and/or alkaline earth metal; and 
 M comprises one or more transition metals stable in a tetracoordinate or hexacoordinate structure, and 
 wherein the molar ratio (A/M) of total alkali metal and/or alkaline earth metal (A) to total transition metal (M) is more than 0 and is not more than 1.5. 
 
     
     
       9. The novel precursor particle according to  claim 8 , wherein the alkali metal comprises one or more of Li (lithium) and Na (sodium). 
     
     
       10. The novel precursor particle according to  claim 8 , wherein the novel precursor particle is a secondary granule formed by aggregation between a plurality of primary particles. 
     
     
       11. The novel precursor particle according to  claim 8 , wherein the alkali metal or alkaline earth metal is present in at least one of the following states:
 (a) coating the surface of the primary particles and/or secondary granules; 
 (b) present in the voids between the primary particles; and 
 (c) present in the inner part of primary particles and/or secondary granules. 
 
     
     
       12. The novel precursor particle according to  claim 8 , wherein one or more of the alkali metal and the alkaline earth metal are contained in both the inner part and the outer part of the transition metal precursor particle. 
     
     
       13. The novel precursor particle according to  claim 8 , wherein parameters in the Formula 2 satisfy one of the following combinations (i) to (vii):
 (i) x=0, y=0 
 (ii) y=0, x=1 
 (iii) x=0, x+y=1 
 (iv) y=0, 0<y<1 
 (v) x=0, 0<y<1 
 (vi) 0 <x<1, 0<y<1, x+y=1 
 (vii) 0<x<1, 0<y<1, x+y<1. 
 
     
     
       14. A cathode active material prepared by firing the novel precursor powder according to  claim 1 . 
     
     
       15. A secondary battery comprising the cathode active material according to  claim 14 .